1. Technical Field
The present exemplary embodiments relate to an image display apparatus, an image display method, and a magnetic resonance imaging apparatus, and particularly relate to an image display apparatus, an image display method, and a magnetic resonance imaging apparatus according to which change in details due to a difference of the imaging methods can be easily observed without moving the observation point between images.
2. Description of Related Art
Conventionally, various diagnoses and treatments are carried out in medical practice with the use of various images that are taken by using various diagnostic imaging apparatuses. For example, when using a Magnetic Resonance Imaging (MRI) apparatus, it can take various kinds of images, for example, a longitudinal relaxation weighted image (T1W image), a transverse relaxation weighted image (T2W image), a proton density image, a flair image, a fat suppression image, a diffusion image, a perfusion image, a functional Magnetic Resonance Imaging (f-MRI) image, and a Magnetic Resonance Spectroscopy (MRS), the list is endless. Moreover, when using an X-ray Computed Tomography (CT) apparatus, it can take a functional image, such as a functional image of a blood flow, as well as a usual anatomical image based on CT values.
Usually, when reading a plurality of different images, for example, films are arranged on a back illuminated translucent viewing surface, or images are arranged on a monitor; and then a diagnosis is carried out while the observer's eyes move from one point to another point corresponding to the same anatomical portion between respective images. According to such diagnosis, because images are read by moving the observer's eyes to respective regions of interest among several kinds of arranged images, it takes a long time to read the images. It is also very difficult to perform a diagnosis while comparing anatomical details between images because it is carried out with movement of the observation point.
For this reason, for example, an ultrasound diagnosis apparatus uses a method of superimposing and displaying a monochrome image and a color image onto both of which the same portion is imaged, which is called a fusion method. Apart from this, another method is proposed of enabling a comparative reading without movement of the observation point when there is a plurality of images taken of the same portion, by displaying the images in substantially the same position on a screen by switching the images one by one (for example, see JP-A 2006-95279 (KOKAI)).
However, according to the conventional technology, it is difficult to observe easily change in details due to a difference of imaging methods. For example, according to display by a fusion method, because at least two images are superimposed, one of the superimposed images is limited to an image of a small spatial resolution, such as a monochrome image, or a topical image. According to the method of displaying images in the substantially same position by switching them, although reduction in movement of observation point is taken into account, observation of change in details due to a difference of imaging methods is not considered.